What most said above is true (I've played my rogue and my bro's warrior), but there is nothing like popping out of stealth with sprint, grabbing the flag and dashing through a room full of defense and then laughing while everyone is probably going 'Wtf??'.
On my rogue I have actually got a good deal of flag returns (relatively [add to that that usually I hand it off to a pally when I'm back at base]). If you have a glyph of sprint especially, that's 80% speed for 15 seconds, and even if you get stunned, as soon as the stun is up you're flying away again. So I wouldn't underestimate rogues as FC's.
A lot of people these days in 19's seems to use rogues in a dual-swords go in and whack things kind of way, and if you go that way you might as well roll warrior. I use rogues in a less 19-WSG traditional way. I do a lot more stealthing around, ambushing people, putting them out of comission, leading them into traps, sapping, etc. Basically, what you have to ask yourself is, what do I want? Do you want to just fight, or do you want to do the sneaky business as well?
As I've learned, rogues also take a ton of skill to be good at, so if you want to get in there and start owning, probably not the right class.